includes/api/ApiQuery.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 7, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if (!defined('MEDIAWIKI')) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ('ApiBase.php');
  29 }
  30
  31 /**
  32  * This is the main query class. It behaves similar to ApiMain: based on the parameters given,
  33  * it will create a list of titles to work on (an instance of the ApiPageSet object)
  34  * instantiate and execute various property/list/meta modules,
  35  * and assemble all resulting data into a single ApiResult object.
  36  *
  37  * In the generator mode, a generator will be first executed to populate a second ApiPageSet object,
  38  * and that object will be used for all subsequent modules.
  39  *
  40  * @addtogroup API
  41  */
  42 class ApiQuery extends ApiBase {
  43
  44         private $mPropModuleNames, $mListModuleNames, $mMetaModuleNames;
  45         private $mPageSet;
  46         private $params, $redirect;
  47
  48         private $mQueryPropModules = array (
  49                 'info' => 'ApiQueryInfo',
  50                 'revisions' => 'ApiQueryRevisions',
  51                 'links' => 'ApiQueryLinks',
  52                 'langlinks' => 'ApiQueryLangLinks',
  53                 'images' => 'ApiQueryImages',
  54                 'imageinfo' => 'ApiQueryImageInfo',
  55                 'templates' => 'ApiQueryLinks',
  56                 'categories' => 'ApiQueryCategories',
  57                 'extlinks' => 'ApiQueryExternalLinks',
  58         );
  59
  60         private $mQueryListModules = array (
  61                 'allpages' => 'ApiQueryAllpages',
  62                 'alllinks' => 'ApiQueryAllLinks',
  63                 'allcategories' => 'ApiQueryAllCategories',
  64                 'allusers' => 'ApiQueryAllUsers',
  65                 'backlinks' => 'ApiQueryBacklinks',
  66                 'blocks' => 'ApiQueryBlocks',
  67                 'categorymembers' => 'ApiQueryCategoryMembers',
  68                 'deletedrevs' => 'ApiQueryDeletedrevs',
  69                 'embeddedin' => 'ApiQueryBacklinks',
  70                 'imageusage' => 'ApiQueryBacklinks',
  71                 'logevents' => 'ApiQueryLogEvents',
  72                 'recentchanges' => 'ApiQueryRecentChanges',
  73                 'search' => 'ApiQuerySearch',
  74                 'usercontribs' => 'ApiQueryContributions',
  75                 'watchlist' => 'ApiQueryWatchlist',
  76                 'exturlusage' => 'ApiQueryExtLinksUsage',
  77                 'users' => 'ApiQueryUsers',
  78                 'random' => 'ApiQueryRandom',
  79         );
  80
  81         private $mQueryMetaModules = array (
  82                 'siteinfo' => 'ApiQuerySiteinfo',
  83                 'userinfo' => 'ApiQueryUserInfo',
  84                 'allmessages' => 'ApiQueryAllmessages',
  85         );
  86
  87         private $mSlaveDB = null;
  88         private $mNamedDB = array();
  89
  90         public function __construct($main, $action) {
  91                 parent :: __construct($main, $action);
  92
  93                 // Allow custom modules to be added in LocalSettings.php
  94                 global $wgApiQueryPropModules, $wgApiQueryListModules, $wgApiQueryMetaModules;
  95                 self :: appendUserModules($this->mQueryPropModules, $wgApiQueryPropModules);
  96                 self :: appendUserModules($this->mQueryListModules, $wgApiQueryListModules);
  97                 self :: appendUserModules($this->mQueryMetaModules, $wgApiQueryMetaModules);
  98
  99                 $this->mPropModuleNames = array_keys($this->mQueryPropModules);
 100                 $this->mListModuleNames = array_keys($this->mQueryListModules);
 101                 $this->mMetaModuleNames = array_keys($this->mQueryMetaModules);
 102
 103                 // Allow the entire list of modules at first,
 104                 // but during module instantiation check if it can be used as a generator.
 105                 $this->mAllowedGenerators = array_merge($this->mListModuleNames, $this->mPropModuleNames);
 106         }
 107
 108         /**
 109          * Helper function to append any add-in modules to the list
 110          */
 111         private static function appendUserModules(&$modules, $newModules) {
 112                 if (is_array( $newModules )) {
 113                         foreach ( $newModules as $moduleName => $moduleClass) {
 114                                 $modules[$moduleName] = $moduleClass;
 115                         }
 116                 }
 117         }
 118
 119         /**
 120          * Gets a default slave database connection object
 121          */
 122         public function getDB() {
 123                 if (!isset ($this->mSlaveDB)) {
 124                         $this->profileDBIn();
 125                         $this->mSlaveDB = wfGetDB(DB_SLAVE);
 126                         $this->profileDBOut();
 127                 }
 128                 return $this->mSlaveDB;
 129         }
 130
 131         /**
 132          * Get the query database connection with the given name.
 133          * If no such connection has been requested before, it will be created.
 134          * Subsequent calls with the same $name will return the same connection
 135          * as the first, regardless of $db or $groups new values.
 136          */
 137         public function getNamedDB($name, $db, $groups) {
 138                 if (!array_key_exists($name, $this->mNamedDB)) {
 139                         $this->profileDBIn();
 140                         $this->mNamedDB[$name] = wfGetDB($db, $groups);
 141                         $this->profileDBOut();
 142                 }
 143                 return $this->mNamedDB[$name];
 144         }
 145
 146         /**
 147          * Gets the set of pages the user has requested (or generated)
 148          */
 149         public function getPageSet() {
 150                 return $this->mPageSet;
 151         }
 152
 153         /**
 154          * Get the array mapping module names to class names
 155          */
 156         function getModules() {
 157                 return array_merge($this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules);
 158         }
 159
 160         /**
 161          * Query execution happens in the following steps:
 162          * #1 Create a PageSet object with any pages requested by the user
 163          * #2 If using generator, execute it to get a new PageSet object
 164          * #3 Instantiate all requested modules.
 165          *    This way the PageSet object will know what shared data is required,
 166          *    and minimize DB calls.
 167          * #4 Output all normalization and redirect resolution information
 168          * #5 Execute all requested modules
 169          */
 170         public function execute() {
 171
 172                 $this->params = $this->extractRequestParams();
 173                 $this->redirects = $this->params['redirects'];
 174
 175                 //
 176                 // Create PageSet
 177                 //
 178                 $this->mPageSet = new ApiPageSet($this, $this->redirects);
 179
 180                 //
 181                 // Instantiate requested modules
 182                 //
 183                 $modules = array ();
 184                 $this->InstantiateModules($modules, 'prop', $this->mQueryPropModules);
 185                 $this->InstantiateModules($modules, 'list', $this->mQueryListModules);
 186                 $this->InstantiateModules($modules, 'meta', $this->mQueryMetaModules);
 187
 188                 //
 189                 // If given, execute generator to substitute user supplied data with generated data.
 190                 //
 191                 if (isset ($this->params['generator'])) {
 192                         $this->executeGeneratorModule($this->params['generator'], $modules);
 193                 } else {
 194                         // Append custom fields and populate page/revision information
 195                         $this->addCustomFldsToPageSet($modules, $this->mPageSet);
 196                         $this->mPageSet->execute();
 197                 }
 198
 199                 //
 200                 // Record page information (title, namespace, if exists, etc)
 201                 //
 202                 $this->outputGeneralPageInfo();
 203
 204                 //
 205                 // Execute all requested modules.
 206                 //
 207                 foreach ($modules as $module) {
 208                         $module->profileIn();
 209                         $module->execute();
 210                         $module->profileOut();
 211                 }
 212         }
 213
 214         /**
 215          * Query modules may optimize data requests through the $this->getPageSet() object
 216          * by adding extra fields from the page table.
 217          * This function will gather all the extra request fields from the modules.
 218          */
 219         private function addCustomFldsToPageSet($modules, $pageSet) {
 220                 // Query all requested modules.
 221                 foreach ($modules as $module) {
 222                         $module->requestExtraData($pageSet);
 223                 }
 224         }
 225
 226         /**
 227          * Create instances of all modules requested by the client
 228          */
 229         private function InstantiateModules(&$modules, $param, $moduleList) {
 230                 $list = $this->params[$param];
 231                 if (isset ($list))
 232                         foreach ($list as $moduleName)
 233                                 $modules[] = new $moduleList[$moduleName] ($this, $moduleName);
 234         }
 235
 236         /**
 237          * Appends an element for each page in the current pageSet with the most general
 238          * information (id, title), plus any title normalizations and missing title/pageids/revids.
 239          */
 240         private function outputGeneralPageInfo() {
 241
 242                 $pageSet = $this->getPageSet();
 243                 $result = $this->getResult();
 244
 245                 // Title normalizations
 246                 $normValues = array ();
 247                 foreach ($pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr) {
 248                         $normValues[] = array (
 249                                 'from' => $rawTitleStr,
 250                                 'to' => $titleStr
 251                         );
 252                 }
 253
 254                 if (!empty ($normValues)) {
 255                         $result->setIndexedTagName($normValues, 'n');
 256                         $result->addValue('query', 'normalized', $normValues);
 257                 }
 258
 259                 // Interwiki titles
 260                 $intrwValues = array ();
 261                 foreach ($pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr) {
 262                         $intrwValues[] = array (
 263                                 'title' => $rawTitleStr,
 264                                 'iw' => $interwikiStr
 265                         );
 266                 }
 267
 268                 if (!empty ($intrwValues)) {
 269                         $result->setIndexedTagName($intrwValues, 'i');
 270                         $result->addValue('query', 'interwiki', $intrwValues);
 271                 }
 272
 273                 // Show redirect information
 274                 $redirValues = array ();
 275                 foreach ($pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo) {
 276                         $redirValues[] = array (
 277                                 'from' => $titleStrFrom,
 278                                 'to' => $titleStrTo
 279                         );
 280                 }
 281
 282                 if (!empty ($redirValues)) {
 283                         $result->setIndexedTagName($redirValues, 'r');
 284                         $result->addValue('query', 'redirects', $redirValues);
 285                 }
 286
 287                 //
 288                 // Missing revision elements
 289                 //
 290                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 291                 if (!empty ($missingRevIDs)) {
 292                         $revids = array ();
 293                         foreach ($missingRevIDs as $revid) {
 294                                 $revids[$revid] = array (
 295                                         'revid' => $revid
 296                                 );
 297                         }
 298                         $result->setIndexedTagName($revids, 'rev');
 299                         $result->addValue('query', 'badrevids', $revids);
 300                 }
 301
 302                 //
 303                 // Page elements
 304                 //
 305                 $pages = array ();
 306
 307                 // Report any missing titles
 308                 foreach ($pageSet->getMissingTitles() as $fakeId => $title) {
 309                         $vals = array();
 310                         ApiQueryBase :: addTitleInfo($vals, $title);
 311                         $vals['missing'] = '';
 312                         $pages[$fakeId] = $vals;
 313                 }
 314
 315                 // Report any missing page ids
 316                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 317                         $pages[$pageid] = array (
 318                                 'pageid' => $pageid,
 319                                 'missing' => ''
 320                         );
 321                 }
 322
 323                 // Output general page information for found titles
 324                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 325                         $vals = array();
 326                         $vals['pageid'] = $pageid;
 327                         ApiQueryBase :: addTitleInfo($vals, $title);
 328                         $pages[$pageid] = $vals;
 329                 }
 330
 331                 if (!empty ($pages)) {
 332
 333                         if ($this->params['indexpageids']) {
 334                                 $pageIDs = array_keys($pages);
 335                                 // json treats all map keys as strings - converting to match
 336                                 $pageIDs = array_map('strval', $pageIDs);
 337                                 $result->setIndexedTagName($pageIDs, 'id');
 338                                 $result->addValue('query', 'pageids', $pageIDs);
 339                         }
 340
 341                         $result->setIndexedTagName($pages, 'page');
 342                         $result->addValue('query', 'pages', $pages);
 343                 }
 344         }
 345
 346         /**
 347          * For generator mode, execute generator, and use its output as new pageSet
 348          */
 349         protected function executeGeneratorModule($generatorName, $modules) {
 350
 351                 // Find class that implements requested generator
 352                 if (isset ($this->mQueryListModules[$generatorName])) {
 353                         $className = $this->mQueryListModules[$generatorName];
 354                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 355                         $className = $this->mQueryPropModules[$generatorName];
 356                 } else {
 357                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 358                 }
 359
 360                 // Generator results
 361                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 362
 363                 // Create and execute the generator
 364                 $generator = new $className ($this, $generatorName);
 365                 if (!$generator instanceof ApiQueryGeneratorBase)
 366                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 367
 368                 $generator->setGeneratorMode();
 369
 370                 // Add any additional fields modules may need
 371                 $generator->requestExtraData($this->mPageSet);
 372                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 373
 374                 // Populate page information with the original user input
 375                 $this->mPageSet->execute();
 376
 377                 // populate resultPageSet with the generator output
 378                 $generator->profileIn();
 379                 $generator->executeGenerator($resultPageSet);
 380                 $resultPageSet->finishPageSetGeneration();
 381                 $generator->profileOut();
 382
 383                 // Swap the resulting pageset back in
 384                 $this->mPageSet = $resultPageSet;
 385         }
 386
 387         /**
 388          * Returns the list of allowed parameters for this module.
 389          * Qurey module also lists all ApiPageSet parameters as its own.
 390          */
 391         protected function getAllowedParams() {
 392                 return array (
 393                         'prop' => array (
 394                                 ApiBase :: PARAM_ISMULTI => true,
 395                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 396                         ),
 397                         'list' => array (
 398                                 ApiBase :: PARAM_ISMULTI => true,
 399                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 400                         ),
 401                         'meta' => array (
 402                                 ApiBase :: PARAM_ISMULTI => true,
 403                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 404                         ),
 405                         'generator' => array (
 406                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 407                         ),
 408                         'redirects' => false,
 409                         'indexpageids' => false,
 410                 );
 411         }
 412
 413         /**
 414          * Override the parent to generate help messages for all available query modules.
 415          */
 416         public function makeHelpMsg() {
 417
 418                 $msg = '';
 419
 420                 // Make sure the internal object is empty
 421                 // (just in case a sub-module decides to optimize during instantiation)
 422                 $this->mPageSet = null;
 423                 $this->mAllowedGenerators = array();    // Will be repopulated
 424
 425                 $astriks = str_repeat('--- ', 8);
 426                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 427                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 428                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 429                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 430                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 431                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 432
 433                 // Perform the base call last because the $this->mAllowedGenerators
 434                 // will be updated inside makeHelpMsgHelper()
 435                 // Use parent to make default message for the query module
 436                 $msg = parent :: makeHelpMsg() . $msg;
 437
 438                 return $msg;
 439         }
 440
 441         /**
 442          * For all modules in $moduleList, generate help messages and join them together
 443          */
 444         private function makeHelpMsgHelper($moduleList, $paramName) {
 445
 446                 $moduleDscriptions = array ();
 447
 448                 foreach ($moduleList as $moduleName => $moduleClass) {
 449                         $module = new $moduleClass ($this, $moduleName, null);
 450
 451                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 452                         $msg2 = $module->makeHelpMsg();
 453                         if ($msg2 !== false)
 454                                 $msg .= $msg2;
 455                         if ($module instanceof ApiQueryGeneratorBase) {
 456                                 $this->mAllowedGenerators[] = $moduleName;
 457                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 458                         }
 459                         $moduleDscriptions[] = $msg;
 460                 }
 461
 462                 return implode("\n", $moduleDscriptions);
 463         }
 464
 465         /**
 466          * Override to add extra parameters from PageSet
 467          */
 468         public function makeHelpMsgParameters() {
 469                 $psModule = new ApiPageSet($this);
 470                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 471         }
 472
 473         // @todo should work correctly
 474         public function shouldCheckMaxlag() {
 475                 return true;
 476         }
 477
 478         protected function getParamDescription() {
 479                 return array (
 480                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 481                         'list' => 'Which lists to get',
 482                         'meta' => 'Which meta data to get about the site',
 483                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 484                         'redirects' => 'Automatically resolve redirects',
 485                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 486                 );
 487         }
 488
 489         protected function getDescription() {
 490                 return array (
 491                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 492                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 493                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 494                 );
 495         }
 496
 497         protected function getExamples() {
 498                 return array (
 499                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 500                 );
 501         }
 502
 503         public function getVersion() {
 504                 $psModule = new ApiPageSet($this);
 505                 $vers = array ();
 506                 $vers[] = __CLASS__ . ': $Id$';
 507                 $vers[] = $psModule->getVersion();
 508                 return $vers;
 509         }
 510 }
 511